https://pdf.yt/d/XYviTa7FvMEcNm_8 / https://www.dropbox.com/s/1b7dhfs7djx1k5j/2014-buehler.pdf?dl=0
https://pdf.yt/d/N7CH7xQxtNnQVy2f / https://www.dropbox.com/s/8mzse6c24dteqy6/2014-velez.pdf?dl=0 / http://sci-hub.org/downloads/b6c8/10.1007@s11749-014-0396-0.pdf
https://pdf.yt/d/XYviTa7FvMEcNm_8 / https://www.dropbox.com/s/1b7dhfs7djx1k5j/2014-buehler.pdf?dl=0
https://pdf.yt/d/N7CH7xQxtNnQVy2f / https://www.dropbox.com/s/8mzse6c24dteqy6/2014-velez.pdf?dl=0 / http://sci-hub.org/downloads/b6c8/10.1007@s11749-014-0396-0.pdf